Warm blood cells rely on a continuous and adequate demand-orientated supply of oxygen so that even a brief interruption in the supply of oxygen can cause irreparable damage in and on the cells, particularly of the central nervous system and the cardiac circulatory system.
A shortage of oxygen, hypoxia, can be caused principally by inadequate supply, disorders of the pulmonary function, disorders in the conveyance of oxygen through the blood or a lack of hemoglobin and also by disorders in the cardiac circulatory system. In emergency medicine as well as in internal clinical supply, therefore, it is standard practice to supply oxygen to a patient. Within the framework of what is referred to as preoxygenation, above all before any intubation, it is vitally necessary to cover the patient's oxygen demand in the dangerous period prior to completion of the intubation or in the event of intubation complications.
In such and other cases, it is vital to enrich the storage space in the lungs with pure oxygen and at the same time also to ensure that other gases present in the body or in the inspired air, above all nitrogen, are as far as possible kept completely away. In most cases, this is either not achieved at all or is achieved only very inadequately by conventional pre-oxygenation methods. Known oxygenation apparatuses are masks, pharyngeal tubes and nasal-pharyngeal tubes, referred to as just tubes.
The disadvantages of these apparatus, described in the literature (e.g. R. G. Sandersen [ed.]: The Cardiac Patient, Philadelphia, W. B. Saunders, 1972, page 310), are above all
insufficient humidification and warming of the gas, PA1 oxygen concentration is never 100%, PA1 re-inhalation of respired air (CO.sub.2 and N.sub.2) and PA1 a very high oxygen flow.
The problem on which the invention is based therefore resides in providing an apparatus for supplying oxygen to a patient (oxygenation), by means of which, simultaneously with the enrichment of oxygen, undesired other gases are as far as possible kept completely out of the pulmonary space.
In addition, it is intended to eliminate the above-mentioned drawbacks of prior art apparatus.